PIR Shield

The PIR Shield wakes the OpenMV Cam from deep sleep on motion, draws an ultra-low 6 µA in standby, and adds eight white plus eight 850 nm infrared LEDs for illumination. Ideal for battery-powered surveillance and trail cameras.

PIR Shield

For full datasheet, photos, and ordering see the PIR Shield product page.

Highlights

  • 6 µA standby PIR sensor for years of battery operation

  • Eight 3500 K white LEDs and eight 850 nm IR LEDs (PWM-dimmable)

Pinout

PIR Shield Pinout

Pin reference

Pin

Function

P7

PWM control for the white LEDs

P8

PWM control for the 850 nm IR LEDs

P9

Wakeup (alternative)

P11

Wakeup (default) — pulls low when the PIR detects motion

RAW rail

Always-on power for the PIR sensor — keeps motion detection alive while the camera is in deep sleep

3.3V rail

Powers the shield’s on-board electronics

GND rail

Common ground

Note

Each of P7, P8, P9, and P11 can be reclaimed for unrelated use. P7, P8, and P11 are connected by default through back-side solder jumpers — open the jumper on any pin you want to free. P9 defaults to disconnected: bridge its back-side jumper to route the wakeup signal to P9 instead (and open P11’s back-side jumper to release P11).

Note

P11 is the wakeup pin on all modern OpenMV Cams — leave the shield on its default mapping for deepsleep() motion wake. The P9 alternative exists for legacy OpenMV Cams, which don’t have a dedicated wakeup line — P9 lands on a regular GPIO that you’d poll or attach an IRQ to instead.

Usage

PWM-dim the white and IR illumination LEDs:

from machine import PWM, Pin

white = PWM(Pin("P7"), freq=50_000, duty_u16=0)
ir = PWM(Pin("P8"), freq=50_000, duty_u16=0)

white.duty_u16(32_768)  # 50% white
ir.duty_u16(16_384)  # 25% IR

Wake the camera from deep sleep on motion. P11 (the default wakeup line) pulls low when the PIR triggers and resets the camera:

from machine import deepsleep

deepsleep()  # the next motion event resets the camera